Articulation and firing force mechanisms

ABSTRACT

There is provided a surgical instrument incorporating driving force mechanisms capable of transmitting a driving force through an articulated section of the surgical instrument. In one embodiment, a series of racks connect with a transfer gear to pass forces around the articulated section. In an alternative embodiment a series of cable sections and wheels or pulleys are provided to transmit a driving force through the articulated section of the surgical instrument.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/623,156 filed Sep. 20, 2012, now U.S. Pat. No. 8,496,152, which is acontinuation of U.S. application Ser. No. 13/095,560 filed Apr. 27,2011, now U.S. Pat. No. 8,292,148, which is a continuation of U.S.application Ser. No. 12/261,283 filed Oct. 30, 2008, now U.S. Pat. No.7,954,685, which claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 60/985,663, filed on Nov. 6, 2007, the entirecontents of each of which are incorporated herein by reference.

BACKGROUND

1. Technical field

The present disclosure relates to firing force mechanisms for use in asurgical instrument. More particularly, the present disclosure relatesto firing force mechanisms capable of transmitting a firing or drivingforce around an angle within a surgical stapling instrument.

2. Background of Related Art

Various surgical instruments are known in the art for performingoperations within a body cavity. Certain of these instruments areconfigured to pass through an access opening in the body of the patient.A handle portion of the instrument remains outside the body while anelongate portion of the instrument passes through the port and into thebody cavity. When these types of devices are utilized, it is oftendifficult to orient the distal end of the elongate portion within bodyby manipulation of the handle portion of the instrument from outside ofthe body.

Unique instruments have been developed which allow the elongate portionof the instrument entering the body to bend or move within the bodyindependent of the position of the handle portion of the instrumentoutside the body. These “articulating” surgical instruments employvarious mechanisms to cause the elongate portion to bend or bereoriented within the body.

While it is relatively easy for the elongate portion of instrument to bebent or reoriented within the body, the ability to transmit an actuationor driving force around the bend to an end effector associated with theelongate portion poses difficulties. These difficulties include loss offorce due to bowing or flexing of the drive elements as they pass aroundthe bend in the elongate portion, etc.

SUMMARY

There is provided a surgical instrument including a handle having anelongate tubular member extending distally from the handle. The elongatetubular member has a proximal portion, a distal portion and anarticulation section positioned between the distal and proximalportions. The articulation section allows the distal portion to moverelative to the proximal section.

A drive force mechanism is provided in the surgical instrument andincludes a drive element positioned in the proximal portion, a transferbar positioned in the distal portion and a transfer device positioned inthe articulation section. The transfer device receives a driving forcefrom the drive element and reorients the driving force around thearticulation section and toward the transfer bar. The transfer device isrotatably mounted in the articulation section.

The transfer device is rotatably mounted in the articulation section. Inone embodiment, the drive element is a gear rotatably mounted at a pointof articulation. The drive element includes a rack engagable with thegear so as to rotate the gear in response to longitudinal motion of therack. The transfer bar includes a rack engagable with the gear such thatrotation of the gear moves the transfer bar longitudinally within thedistal portion.

In an alternative embodiment the transfer device includes at least onewheel rotatably mounted in the articulation section. The drive elementis a flexible cable which passes around the at least one wheel. Thedrive mechanism includes a toggle rotatably mounted in the distalportion, a first end of the toggle being connected to the transfer bar.A second end of the toggle is connected to the cable. The cable has anupper section and a lower section, the upper section being connected tothe first end of the toggle and the lower section being connected to thesecond end of the toggle.

The surgical instrument further includes an actuator positioned in thedistal portion to operate an end effector associated with the surgicalinstrument. The transfer bar is engagable with the actuator and includesa drive tooth engagable with the actuator.

In a specific embodiment, the drive tooth is releasably engagable withthe actuator. The actuator includes a plurality of abutments and thedrive tooth includes a drive face engagble within the abutments. Thedrive tooth also includes a proximal sloped face, the proximal slopedface is engagable with the abutments to disengage the drive tooth fromthe abutments.

DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently driving force mechanisms aredisclosed herein with reference to the drawings, wherein:

FIG. 1 is a perspective view of an articulating surgical staplerincorporating a first embodiment of a driving force mechanism;

FIG. 2 is a side view, partially shown in section, of a handle assemblyof the surgical stapler of FIG. 1;

FIG. 3 is an enlarged perspective view, partially shown in section, of adistal end portion of the surgical stapler of FIG. 1, in anon-articulated position;

FIG. 4 is a perspective view of force transferring components of thesurgical instrument of FIG. 1;

FIG. 5 is a perspective view, partially shown in section, of the distalend portion of the surgical stapler of FIG. 1 shown in an articulatedposition, positioned about a tissue section;

FIG. 6 is a perspective view similar to FIG. 5 during actuation of thesurgical stapler;

FIG. 7 is an enlarged perspective view illustrating a portion of thedriving force mechanism resetting for a further actuation of thesurgical stapler;

FIG. 8 is an enlarged side view, partially shown in section, of a staplecartridge and anvil of the surgical stapler during initial actuation;

FIG. 9 is an enlarged side view, similar to FIG. 8, illustrating furtheractuation of the surgical stapler to staple the tissue section;

FIG. 10 is a side view, partially shown in section, of a handle assemblyof a surgical stapler incorporating an alternative embodiment of adriving force mechanism;

FIG. 11 is a perspective view, partially shown in section, of a distalend portion of the surgical stapler of FIG. 10, shown in anon-articulated position;

FIG. 12 is a perspective view, partially shown in section, of the distalend portion of the surgical stapler of FIG. 10, shown in an articulatedposition, positioned about tissue;

FIG. 13 is a perspective view similar to FIG. 12 during actuation; and

FIG. 14 is an enlarged perspective view of a portion of the drivingforce mechanism resetting for a further actuation.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed driving force mechanisms for usein surgical instruments will now be described in detail with referenceto the drawings wherein like numerals designate identical orcorresponding elements in each of the several views. As is common in theart, the term “proximal” refers to that part or component closer to theuser or operator, i.e. user, surgeon or physician, while the term“distal” refers to that part or component further away from the user.

FIG. 1 illustrates a surgical stapler 10 incorporating one embodiment ofa driving force mechanism. Surgical stapler 10 generally includes ahandle 12 and a distal end portion 14 extending distally from handle 12.Distal end portion 14 is configured for endoscopic use and includes anelongate tubular member 16 extending from a distal end 18 of handle 12.A jaw assembly 20 is mounted on a distal end 22 of elongate tubularmember 16 and includes a staple cartridge 24 and an anvil 26. Anvil 26is mounted for movement between an open position spaced apart fromstaple cartridge to a closed position substantially adjacent staplecartridge 24. A trigger 28 is provided on handle 12 to actuate jawassembly 20.

Surgical stapler 10 is of the type of surgical instruments that arecapable of bending or articulating about an articulation section 30 inelongate tubular member 16. Articulation section 30 is located aboutmidway along elongate tubular member 16 separating elongate tubularmember 16 into a distal portion 32 and a proximal portion 34. Elongatetubular member 16 bends about an axis “A” of articulation section 30through an angle α. An articulation actuator 36 is provided on handle 12to move distal portion 32 relative to proximal portion 34 about axis A(shown in FIGS. 1, 2). Articulation actuator 36 moves articulators 40and 42 which extend from articulation actuator 36 to articulationsection 30. (See FIG. 5) While not specifically shown, variousmechanisms are known in the art which are capable of effecting angularmovement of distal portion 32 of elongate tubular member 16 relative toproximal portion 34 of elongate tubular member 16 about axis A andthrough angle α. For example, linkages, flexible bands, gears, etc. In aparticular embodiment angle α can be between about 0° to about 90° ormore from the longitudinal axis of the proximal portion 34.

In order to properly orient jaw assembly 20 relative to tissue, surgicalstapler 10 includes a rotation knob 44 rotatably mounted on handle 12.Elongate tubular member 16 is mounted in a nose cone portion 46 ofrotation knob 44 and a knurled portion 48 is provided on rotation knob44 to facilitate rotation of distal end portion 14 relative to handle12.

Referring to FIG. 2, a driver 50 is mounted for longitudinal movementwithin handle 12. A pair of guide rails 52 and 54 are provided in handleto support driver 50. As noted above, trigger 28 is provided to actuatejaw assembly 20. Trigger 28 is pivotally mounted on a pivot post 56formed in handle 20. An upper end 58 of trigger 28 is connected todriver 50 by a pivot pin 60. Movement of trigger 28 translates driver 50within handle 12 to actuate jaw assembly 20. A return spring 62 ispositioned over pivot post 56 and is engagable at a first end 64 with aprojection 66 formed in handle 12. A second end 68 of guide spring 64engages trigger 28 to bias trigger 28 to an open or unfired position.

As noted above, surgical stapler 10 includes a drive force mechanism inorder to transfer an actuation force from trigger 28 to jaw assembly 20.The drive force mechanism includes a drive bar 70 provided withinproximal portion 34 of elongate tubular member 16. Drive bar 70 isconnected at its proximal end 72 to a rotation collar 74 rotatablymounted in handle 12. Rotation collar 74 is connected to a distal end 76of driver 50. Rotation collar 74 is provided to allow drive rod 70, aswell as other driving force mechanism components, to rotate as distalend portion 14 is rotated through manipulation of rotation knob 44.

Referring now to FIG. 3, drive rod 70 extends through proximal portion34 to articulation section 30. A distal end 78 of drive rod 70 includesa first rack 80 to facilitate transfer of a driving force around andthrough articulation section 30. Drive rod 70 is routed through a guidetube 82 mounted within proximal portion 34 of elongate tubular member 16to separate driving mechanism components from articulation components.In order to transfer a driving force through articulation section 30, atransfer device, such as transfer gear 84, is rotatably mounted withinarticulation section 30 on a center spindle 86. Center spindle 86 ismounted within articulation section 30 along axis A. Transfer gear 84 isengagable with drive rod 70 in a manner discussed hereinbelow. Atransfer bar 88 is provided within distal portion 32 of elongate tubularmember 16 and is provided to transmit forces received from drive rod 70to jaw assembly 20. Transfer bar 88 includes a second rack 90, at aproximal end 92 thereof, which is engagable with transfer gear 84. Adistal end 94 of transfer bar 88 terminates in a drive tooth 96.

Referring to FIG. 4, first rack 80 includes a plurality of first teeth98 which are engagable with gear teeth 100 formed on transfer gear 84.Likewise, second rack 90 includes a plurality of teeth 102 alsoengagable with gear teeth 100 on transfer gear 84. Thus, as drive rod 70moves longitudinally, first rack 80 rotates transfer gear 84 which inturn drives transfer bar 88 longitudinally within distal portion 32.

Referring back to FIG. 3, an actuator 104 is movably mounted withindistal portion 32. A distal end 106 of actuator 104 includes a crossbar108 which is engagable with an angled edge of anvil 26 to move anvil 26between the open and closed positions. While not specifically shown, aknife is also associated with distal end 106 of actuator 104 to severtissue captured between anvil 26 and staple cartridge 24. Anvil 26includes a longitudinal slot 112 to allow passage of the knife throughjaw assembly 20.

In order to receive the driving force from transfer bar 88, a proximalend 114 of actuator 104 is provided with a series of abutments 116engagable with drive tooth 96 at distal end 94 of transfer bar 88. (SeeFIGS. 3 and 7) Drive tooth 96 repeatedly engages subsequent abutments116 to incrementally advance actuator 104 within distal portion 32 andthus actuate jaw assembly 20. Actuator 104 is supported for longitudinalmotion within distal portion 32 by a pair of guide channels 118 and 120.The abutments 116 may be formed as surfaces defining windows in theactuator 104, notches, pins or teeth.

The use of the disclosed driving force mechanism of surgical stapler 10to transmit a driving force around a bend in surgical stapler will nowbe described. Referring initially to FIGS. 2 and 3, surgical stapler 10is in an initial position with spring 62 biasing trigger 28 to the openor unfired position. Upper end 58 of trigger 28 places driver 50, andthus drive bar 70, in a proximal position within handle 12 (FIG. 2). Asshown in FIG. 3, distal portion 32 of elongate tubular member 16 is inlongitudinal alignment with proximal portion 34 and anvil 26 is in theopen position spaced apart from staple cartridge 24. Transfer bar 88 andactuator 104 are also in proximal positions within distal portion 32.

Referring now to FIGS. 1 and 5, upon actuation of articulation actuator36 (FIG. 1), articulators 40 and 42 are activated to cause elongatetubular member 16 to bend at axis A in articulation section 30 therebypositioning distal portion 32 of elongate tubular member 16 at an angleof approximately 90° relative to proximal portion 34 (FIG. 5). As notedabove, various mechanisms and methods are well known in the art toaccomplish the bending or articulation at articulation section 30. Jawassembly 16 is initially positioned about a tissue section “T” to beoperated on.

Referring to FIGS. 1 and 6, trigger 28 is actuated or squeezedproximally causing upper end 58 to drive driver 50 distally withinhandle 12. As driver 50 moves distally it moves drive bar 70 distallywithin proximal portion 34 of elongate tubular member 16. As best shownin FIG. 6, distal movement of drive bar 70 rotates transfer gear 84clockwise about axis A and in the direction of arrow B. Specifically,first teeth 98 of drive bar 70 engages and rotates gear teeth 100 oftransfer gear 84. Transfer gear 84 receives the driving force from drivebar 70 and transfers or “redirects” the force through angle α, here 90°,to transfer bar 88. Specifically, gear teeth 10 engage second teeth 102in second rack 90 forcing transfer bar distally within distal portion 32of elongate tubular member 16. Thus, the combination of drive bar 70including first rack 80, transfer gear 84 and transfer bar 88 includingsecond rack 90 form a drive force transfer or “redirecting” mechanismallowing a drive force to be transmitted through an angle formed in aportion of surgical stapler 10. As noted above, drive force mechanismsdisclosed herein are equally applicable to other surgical instruments,such as, for example, graspers, cutters, clip appliers, etc. Further,the disclosed drive force mechanisms are equally applicable in othersurgical instruments having articulation sections located at otherpositions on the surgical instrument, for example, at the juncture of ahandle and elongate tubular member, adjacent an end effector, etc.

Referring to FIG. 7, as noted above, drive tooth 96 on transfer bar 88engages sequential abutments 116 in ratchet or incremental fashion tomove actuator 104 distally within distal portion 32 thereby actuatingjaw assembly 20. In some cases it may be necessary to provide multipleactivations of trigger 28 to fully actuate jaw assembly 20. For eachactivation of trigger 28, transfer bar 88 and specifically drive tooth96 moves through a stroke length d1. Drive tooth has a distal drive face122 to engage abutments 116. In order for transfer bar to pass through areturn stroke, drive tooth 96 includes a proximal sloped face 124 whichallows drive tooth 96 to disconnect from or “slip out of” abutments 116.Further activation of trigger 28 causes distal drive face 122 of drivetooth 96 to engage subsequent abutments 116. Guide rails 126 and 128 areprovided within distal portion 32 to allow distal end 94 of transfer bar88 to move laterally away from abutments 116, as well as guide transferbar 88 in its longitudinal motion within distal portion 32.

Referring to FIGS. 6 and 8, upon full actuation, cross bar 108 ofactuator 104 engages angled edge 110 on anvil 26 moving anvil 26 to theclosed position relative to staple cartridge 24.

Referring now to FIG. 9, upon further actuation of surgical stapler 10,a staple bar 130 associated with actuator 104 is moved distally throughstaple cartridge 24 as actuator 104 moves distally through slot 112 inanvil 26. Staple bar 130 engages pushers 132 positioned within staplepockets 134 in staple cartridge 24. Pushers 132 drive staples 136, alsopositioned within staple pockets 134, toward anvil 26 such that pointedends 138, 140 are driven through tissue T and into staple clinchingpockets 142 in anvil 26 to thereby staple tissue section T. As notedabove, a knife associated with actuator 104 moves distally with crossbar 108 to sever tissue T between the staple lines formed by staples136.

Referring now to FIGS. 10-14, there is disclosed another embodiment of adrive force mechanism for use in surgical instruments such as surgicalstapler 10. With initial reference to FIG. 10, surgical stapler 10 is asdescribed hereinabove. However, in place of drive bars, racks and gears,the disclosed alternative embodiment includes a cable, wheel and/orpulley system to transfer a driving force from trigger 28 around andthrough articulation section 30 and to jaw assembly 20. Specifically, awheel 150 is rotatably mounted on a pivot 152 in handle 12. Upper end 58is connected to drive wheel 150 at pivot pin 60 so as to rotate drivewheel 150 in response to activation of trigger 28. A drive cable 154passes around wheel 150 and extends through proximal portion 34 ofelongate tubular member 16 and through articulation section 30 to distalportion 32 of elongate tubular member 16. Drive cable 154 is formed froma flexible material so as to pass around wheel 150. Drive cable 154includes an upper section 156 and a lower section 158. As trigger 28 isactivated, upper end 58 of trigger 12 rotates wheel 150 clockwise inhandle 12 to advance upper section 156 distally and draw lower section158 proximally within elongate tubular member 16. A collar 160 isprovided within handle 12 and allows drive cable 154 to rotate aselongate tubular member 16 rotates in the manner described hereinabove.

Referring to FIG. 11, in order to pass the driving forces from drivecable 154 to actuator 104, a lever 162 is provided within distal portion32 and pivotally mounted at a pivot point 166 on a centerpost 164. Adistal end 168 of upper section 156 of drive cable 154 is connected to afirst end 170 of lever 162 and a distal end 172 of lower section 158 isconnected to a second end 174 of lever 162.

As noted above, the disclosed drive force mechanisms incorporatetransfer devices positioned within articulation section 30 of surgicalstapler 10 to transfer and redirect a driving force passing thoughelongate tubular member 16 as elongate tubular member 16 is bent throughan angle α. In this embodiment, the transfer device is in the form of apair of wheels, including an upper wheel 176 and a lower wheel 178,rotatably mounted on a spindle 180 positioned within articulationsection 30. Spindle 180 is located on axis A of surgical stapler 10.

A transfer bar 182 is positioned within distal portion 32 to transferforces between lever 162 and actuator 104. A proximal end 184 is affixedto first end 178 of lever 162 and a distal end 186 of transfer bar 182is attached to a drive tooth 188 which functions substantiallyidentically to drive tooth 96, described hereinabove, to engageabutments 116 and advance actuator 104 within distal portion 32.

Referring now to FIGS. 10-14, and initially with reference to FIGS. 10and 11, in use, trigger 28 is in the unfired position with wheel 150 atrest. Proximal portion 34 of elongate tubular member 16 is inlongitudinal alignment with articulation section 30 and distal portion32. Anvil 26 is in the open position spaced apart from staple cartridge24.

Referring to FIGS. 10 and 12, as discussed hereinabove, articulationactuator 36 is activated to bend elongate tubular member 16 atarticulation section 30 and position jaw assembly 16 relative to atissue section “T” such that anvil 26 and staple cartridge 24 arepositioned about a tissue section T. Trigger 28 is activated to rotatewheel 150 clockwise drawing lower section 158 of drive cable 154proximally and forcing or allowing upper section 156 to move distally.

As shown in FIG. 12, upper section 156 of drive cable 154 passes aroundupper wheel 176 in articulation section 30 while lower section 158passes around lower wheel 178. As lower section 158 is drawn proximally,lower section 158 pulls on second end 174 of lever 162, rotating lever162 clockwise and driving first end 170 of lever 162 distally. Distalmovement of first end 170 drives transfer bar 182 distally causing drivetooth 188 to engage a abutment 116 and advance actuator 104 distallywithin distal portion 32 of elongate tubular member 16.

Referring to FIG. 13, and as discussed hereinabove, distal movement ofactuator 104 forces crossbar 108 against angled edge 110 of anvil 26 tomove anvil 26 to the closed position relative to staple cartridge 24.Subsequent activations of trigger 28 will result in further actuation ofsurgical stapler 10 to staple tissue T in the manner describedhereinabove.

Referring to FIG. 14, drive tooth 188 also passes through stroke d1 toincrementally advance actuator 104 by successive engagements withabutments 116. Drive tooth 188 includes a distal drive face 190 forengagement with abutments and a proximal sloped face 192 which allowsdrive tooth 188 to disengage from a abutment 116 on a return stroke ofdrive tooth 188 and reengage a subsequent abutment 116.

In this manner the above described drive force mechanisms allow adriving force to be transmitted from a handle of the surgical instrumentaround an articulated section in the surgical instrument and,ultimately, transmitted to a jaw assembly of the surgical instrument.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, other activation mechanismsmay be provided, such as, for example, gas powered, etc. Further, thedisclosed driving force mechanisms are equally suited for use insurgical instruments having articulation point at or close to associatedend effectors. Therefore, the above description should not be construedas limiting, but merely as exemplifications of particular embodiments.Those skilled in the art will envision other modifications within thescope and spirit of the claims appended hereto.

The invention claimed is:
 1. A surgical instrument comprising: anelongate member having a proximal portion and a distal portion, theelongate member defining a longitudinal axis that extends through theproximal and distal portions; a transfer bar supported by the distalportion and adapted to articulate relative to the proximal portion aboutan axis of articulation that extends between the proximal and distalportions; a drive element adapted to direct a drive force through theelongate member; and a transfer device supported within the elongatemember and adapted to redirect the drive force around the axis ofarticulation and toward the transfer bar.
 2. The surgical instrument asrecited in claim 1, wherein the transfer device is mounted between theproximal and distal portions.
 3. The surgical instrument as recited inclaim 2, wherein the transfer device includes a gear.
 4. The surgicalinstrument as recited in claim 3, wherein the drive element includes arack engagable with the gear so as to rotate the gear in response tolongitudinal motion of the rack.
 5. The surgical instrument as recitedin claim 3, wherein the transfer bar is engageable with the gear suchthat rotation of the gear moves the transfer bar longitudinally withinthe distal portion.
 6. The surgical instrument as recited in claim 5,further comprising an end effector supported on the elongate member andan actuator positioned in the distal portion of the elongate member, theactuator adapted to operate the end effector.
 7. The surgical instrumentas recited in claim 6, wherein the transfer bar includes a drive toothreleasably engageable with the actuator.
 8. The surgical instrument asrecited in claim 7, wherein the actuator defines a plurality ofabutments, the drive tooth being selectively positionable within theabutments to actuate the end effector upon the reception of the drivingforce.
 9. The surgical instrument of claim 8, wherein the transfer baris distally advanceable to sequentially position the drive tooth withinadjacent abutments to ratchet the actuator and sequentially actuate theend effector.
 10. The surgical instrument as recited in claim 1, whereinthe drive force is a firing force that facilitates the firing of thesurgical instrument.
 11. The surgical instrument as recited in claim 1,wherein the transfer device includes at least one wheel.
 12. Thesurgical instrument as recited in claim 11, wherein the drive elementincludes a flexible cable adapted to move around the at least one wheel.